In the past it has been known to seal panels and funnels together to form a bulb for a TV picture tube. The sealing edges of the panels and funnels were separately ground to a flat plane and then acid fortified to eliminate the detrimental effects of cracks and crazings caused by the grinding operation. The funnels and panels were then subsequently sealed together along such finished seal edges by means of a frit, which upon the application of heat, fused and hermetically sealed the funnels and panels together.
The present invention sets forth a novel method of eliminating and grinding and acid polishing step heretofore required, and accordingly overcomes the environmental problem of disposing waste etching acids, by substituting a thermally controlled edge contouring step for reshaping the sealing edges to a desired uniform surface contour.